One of the simplest techniques to increase the amount of training data is to flip the field around proper axis.
Hasegawa et al. [1]} used the flipping technique for their training data, which is a laminar periodic shedding behind a bluff body.
Analogous to this study, we also apply the technique to the cylinder wake as shown in figure REF .
Since the cylinder wake data is statistically symmetrical with the horizontal axis, we can simply get the snapshot of half-cycle ahead (or ago), meaning that we could double the number of training snapshots such that,
\(n_{\rm flip} = 2n_{\rm DNS},\) 
